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SMART attribute: Percentage Used

Joined
Jan 21, 2021
Messages
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So my current laptop, a Surface Laptop 2 (c. 2018) has a 256GB SK Hynix BC501 SSD. Oddly it's wired at PCIe 3.0 x2, not sure if this is because flash performance wouldn't be improved at x4 so they used an x2 controller, or if the Intel Sunrise Point chipset (series for U processors) has limited lanes. It's not really relevant, but if anyone knows the answer off-hand, I'm curious.

But not as curious as the Percentage Used attribute of the drive, though! Which at this point in time has risen to a startling 72%!! The amount Microsoft charges for Surface Laptop upgrades is kind of absolutely ridiculous for what you get (extra RAM, CPU upgrades, and storage), so I only did the $200 to upgrade from the base model (128GB storage/8GB RAM) to 256GB/8GB because 128 is just not enough when it's not expandable and there's not even a micro SD slot (like the Surface Go tablet I had) to add space. The 16GB memory option? If MY memory serves, for that it was an extra $250 (two-hundred fifty...). Back in 2018, 8GB RAM was still said to be enough for day to day stuff, and I found it to be - unless I got carried away... The 25W limit (8250U in 25W mode is what the Surface Laptop 2 comes configured with (1.8GHz base instead of 1.6), pretty much kept me to under 8GB RAM in most circumstances. More recently, though, like in the past 2 years, it's been increasingly easy to fill up, so the page file gets used more often, which is more HDD access.

72% wear - how many TB is that that has been written to this 256GB drive? Sadly, not that much - right now the reading is just 21.28TB. Another observation I've made: since I started hitting the RAM's limit and hitting the page file more, the wear is increasingly nonlinearly - I'm pretty sure a few months ago I had 18TB or so written to the drive, and there was less than 50% wear. Since the total wear today is 21.28TB and not 10.73TB (which it would be if a few months ago I had 3.28TB less written and 50% wear), something is different.

Funny thing, I'm someone who often reloads the OS of his systems on a semi-regular basis - it's rare for a system to have an OS installed for over a year. This laptop, because I use it less and for a more limited number of things, I guess I never got to it! Well I did once, like 4 months after I bought it, but never after... It shipped with Windows 10, and I upgraded that to 11 about 8 months after they started offering the upgrade, but other than that, the OS is original. The reason I'm mentioning this is because I have noticed some decrease in write performance, but it's not any worse than I'd expect from an OS that hasn't been reinstalled in well over 5 years. Write performance is slightly degraded as well, but all things considered, I think it'd disappear if I reinstalled Windows...

My questions:
What's going to happen to my drive when it reaches 100% wear (sometimes described as "0% remaining")? Is the drive just going to be slower? If so, will it affect read and write, or just read performance? Is 4k performance more affected than sequential? Will it generate more heat when it's working? My first SSD, a 120GB Vertex 3 Max IOPS Edition, has about 25TB written to it and reports its wear as 2%, so I don't know what to expect... My next hard drive, Samsung 850 EVO 250GB, also reports something like 90% remaining. Both drives perform as new
 
What's going to happen to my drive when it reaches 100% wear (sometimes described as "0% remaining")? Is the drive just going to be slower?
I guess that depends on how the manufacturer set up the "percentage used" attribute. Is it based on TB written? Or is it an actual wear indicator? It's rare that one can see into these things, so it's hard to know.

On another note, if you care about the SSD's wear, then
1. Move your page file to another drive (or get rid of it altogether), and
2. Don't reinstall your OS unless you have to. Regular installs were necessary back in the days of spinning drives when a bloated registry could extend your boot time by minutes. SSDs load small files almost instantaneously, so even with a massive bloat in your registry, you only lose a couple of seconds at most. My current Windows installation has survived 3 complete system upgrades and it's still up and running like on day one.
 
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I guess that depends on how the manufacturer set up the "percentage used" attribute. Is it based on TB written? Or is it an actual wear indicator? It's rare that one can see into these things, so it's hard to know.

On another note, if you care about the SSD's wear, then
1. Move your page file to another drive (or get rid of it altogether), and
2. Don't reinstall your OS unless you have to. Regular installs were necessary back in the days of spinning drives when a bloated registry could extend your boot time by minutes. SSDs load small files almost instantaneously, so even with a massive bloat in your registry, you only lose a couple of seconds at most. My current Windows installation has survived 3 complete system upgrades and it's still up and running like on day one.

I know I wrote a lot, so not sure if you saw: "72% wear - how many TB is that that has been written to this 256GB drive? Sadly, not that much - right now the reading is just 21.28TB. Another observation I've made: since I started hitting the RAM's limit and hitting the page file more, the wear is increasingly nonlinearly - I'm pretty sure a few months ago I had 18TB or so written to the drive, and there was less than 50% wear. Since the total wear today is 21.28TB and not 10.73TB (which it would be if a few months ago I had 3.28TB less written and 50% wear), something is different." - does this indicate it's measuring wear and not just TBW? The last few TBW have been a different type than most of the rest, from page file rather than normal operation as auxiliary laptop. Reason being laptop has 8GB RAM, which up 'til 2022 or so was normally enough for it.

1.) The laptop is a Surface Laptop 2, so its innards are inaccessible. WiFi card break? New laptop. SSD break? New laptop. Power port break? New laptop (fortunately it's magnetic and impossible to physically break, but some silicon to turn 15V to xV could...

2.) I know I wrote a lot, so not sure if you saw: "The reason I'm mentioning this is because I have noticed some decrease in write performance, but it's not any worse than I'd expect from an OS that hasn't been reinstalled in well over 5 years." - I've been contemplating a fresh OS installation - it's only ever had one, and that was relatively shortly after purchase...
 
Is the SSD nearly full? If it is, try to move some data elsewhere and keep about 10% free, preferably more.

The BC501 exists as a discrete SSD so it might actually sit in a M.2 slot but Surfaces are about 50% glue by volume, which makes it nearly impossible to reach the SSD.
 
The SSD in series 2 Surface is soldered in, you can't put a new one by yourself sadly enough... :mad: In the 3 series you actually can exchange it for a new one, but at a high risk of breaking something inside.
 
I know I wrote a lot, so not sure if you saw: "72% wear - how many TB is that that has been written to this 256GB drive? Sadly, not that much - right now the reading is just 21.28TB. Another observation I've made: since I started hitting the RAM's limit and hitting the page file more, the wear is increasingly nonlinearly - I'm pretty sure a few months ago I had 18TB or so written to the drive, and there was less than 50% wear. Since the total wear today is 21.28TB and not 10.73TB (which it would be if a few months ago I had 3.28TB less written and 50% wear), something is different." - does this indicate it's measuring wear and not just TBW? The last few TBW have been a different type than most of the rest, from page file rather than normal operation as auxiliary laptop. Reason being laptop has 8GB RAM, which up 'til 2022 or so was normally enough for it.

1.) The laptop is a Surface Laptop 2, so its innards are inaccessible. WiFi card break? New laptop. SSD break? New laptop. Power port break? New laptop (fortunately it's magnetic and impossible to physically break, but some silicon to turn 15V to xV could...

2.) I know I wrote a lot, so not sure if you saw: "The reason I'm mentioning this is because I have noticed some decrease in write performance, but it's not any worse than I'd expect from an OS that hasn't been reinstalled in well over 5 years." - I've been contemplating a fresh OS installation - it's only ever had one, and that was relatively shortly after purchase...
I read your post, then I gave you my 2 cents on what you can do to prolong your drive's life. Do with it what you will. ;)
 
That soldered-in SSD is even worse; It has no own installed mini PCIE stick, but the parts are soldered onto the motherboard, same as Apple is doing.:twitch:
 
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